Biosorption for Metal Ions Removal from Aqueous Solutions: a Review of Recent Studies

The presence of metal ions in aqueous solutions represents a major environmental problem. These inorganic species are persistent and non-biodegradable pollutants that should be eliminated from water. In the recent years biosorption have emerged as an economical and environmental friendly method for the decontamination of polluted water. The present work represents a review of the recently published literature discussing the use of non-modified biosorbents for the removal of metal ions from aqueous solution. In this review the main classes of biomass materials used as biosorbents are discussed along with the principle factors affecting the biosorption process such as: solution pH, biomass dose, metal ion concentration and contact time. The potential health and environmental hazards of metal ions in addition to the kinetic and isothermal models usually assessed to fit the biosorption experimental data were also reviewed.